Game asking for more lines than a map has

[RighteousRyan1]

I've been tinkering with map-making recently, and I came across this strange issue:

I made a boxed map, like so:

Once I realized the collisions were broken, I decided to test things by going back to the line on the bottom, so the fighters could stand:

Now, the game itself crashes when attempting to load, with said error:

It's trying to load lines that don't exist. It's trying to load line 5 when there is only line 0. Is HSDRaw not resizing the lines array properly in some cases?